I can't see any image (resium)

I am using resium and trying to display an image in billboard but i can’t see it. Why is that? I have looked at many sources and still can’t fix it.

This is my code:

import React from "react";
import { Cartesian3, Color } from "cesium";
import { Viewer, Entity, CameraFlyTo, BillboardGraphics } from "resium";
import './App.css';

export default function App() {
   return (
      <Viewer full>
            <Entity
            name="TEST"
            position={Cartesian3.fromDegrees(-74.015494, 40.704100, 10)}>
            <BillboardGraphics image="testimage.png" />
            </Entity>
            <CameraFlyTo destination={Cartesian3.fromDegrees(-74.015494, 40.704100, 2000)} duration={5.0}/>
      </Viewer>
   );
}